Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Aug 19;22(8):1294.
doi: 10.3390/ijerph22081294.

Using Functional Near-Infrared Spectroscopy to Elucidate Neurophysiological Mechanism of Action of Equine-Assisted Services: Proof-of-Concept Study

Beth A Lanning  1 , Cory M Smith  2 , Cierra Ugale  2 , Elena Nazarenko  3 , William R Marchand  3   4   5
Affiliations

Using Functional Near-Infrared Spectroscopy to Elucidate Neurophysiological Mechanism of Action of Equine-Assisted Services: Proof-of-Concept Study

Beth A Lanning et al. Int J Environ Res Public Health. .

Abstract

Equine-assisted services (EAS) are used for civilian and military trauma survivors to reduce depression and posttraumatic stress symptoms. While early scientific evidence supports the benefits of EAS, the neurophysiological mechanisms underlying these benefits are unknown. The specific aims of this exploratory study were to determine (1) whether functional near-infrared spectroscopy (fNIRS) neuroimaging can be used to explore neural responses of EAS veteran participants and (2) the correlation between neural responses and psychological outcomes of the participants interacting with equines. Fifteen veterans participated in a 2-day EAS program consisting of four randomized activities. An fNIRS sensor cap was used to measure the oxygenated (O2Hb), deoxygenated (hHb), and total hemoglobin (tHb) of the participants during each activity. The results indicated no significant differences for O2Hb and tHb across the visits or activities, however, a significant difference in hHb was observed. There was an increase in hHb during the activities that included an equine, which indicated a greater cognitive load and attention. Further, data from pre-/post-psychometric assessments showed a significant improvement in participants' trait anxiety, psychological flexibility, and positive and negative affect after interacting with the horse. Preliminary data revealed a potential association between the cognitive attention and psychological health of participants during an EAS session.

Keywords: PTSD; equine-assisted services; fNIRS; neurophysiology; psychological flexibility; veterans.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflicts of interest.

Figures

Figure 1
Figure 1
Mean ± SD of the Oxygenated hemoglobin (Hb) responses at Visit 1 and Visit 2 during the Meditation, Leading, Grooming, and Processing tasks.
Figure 2
Figure 2
Mean ± SD of the Deoxygenated hemoglobin (hHb) responses at Visit 1 and Visit 2 during the Meditation, Leading, Grooming, and Processing tasks. * Indicates Visit 2 was significantly greater than Visit 1.
Figure 3
Figure 3
Mean ± SD of the Total hemoglobin (tHb) responses at Visit 1 and Visit 2 during the Meditation, Leading, Grooming, and Processing tasks.
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Goldstein R.B., Smith S.M., Chou S.P., Saha T.D., Jung J., Zhang H., Pickering R.P., Ruan W.J., Huang B., Grant B.F. The epidemiology of DSM-5 posttraumatic stress disorder in the United States: Results from the national epidemiologic survey on alcohol and related conditions-III. Soc. Psychiatry Psychiatr. Epidemiol. 2016;51:1137–1148. doi: 10.1007/s00127-016-1208-5. - DOI - PMC - PubMed
    1. American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders (DSM-5). American Psychiatric Pub. 2013. [(accessed on 6 January 2025)]. Available online: https://psycnet.apa.org/record/2013-14907-000.
    1. Kessler R.C., Wang P.S. The descriptive epidemiology of commonly occurring mental disorders in the United States. Ann. Rev. Public Health. 2008;29:115–129. doi: 10.1146/annurev.publhealth.29.020907.090847. - DOI - PubMed
    1. Lang A.J., Hamblen J.L., Holtzheimer P., Kelly U., Norman S.B., Riggs D., Schnurr P.P., Wiechers I. A clinician’s guide to the 2023 VA/DOD clinical practice guideline for management of posttraumatic stress disorder and acute stress disorder. J. Traum. Stress. 2024;37:19–34. doi: 10.1002/jts.23013. - DOI - PubMed
    1. Vella E.J., Milligan B., Bennett J.L. Participation in outdoor recreation program predicts improved psychosocial well-being among veterans with post-traumatic stress disorder: A pilot study. Mil. Med. 2013;178:254–260. doi: 10.7205/MILMED-D-12-00308. - DOI - PubMed

LinkOut - more resources